C states changing voltage/multi?

[shwick]

I tried disabling three options in my xtreme3 gen3 bios to see if it would stem the multiplier fluctuations in my 2500k.

CPU C3 State Support
CPU C6 State Support
Package C State Support

When disabled my voltage at idle jumped to 1.33v, even though offset was set to only +0.05.

I think it helped a bit with the multiplier fluctuations, but I didn't like that idle voltage.

I enabled the options and idle is at 1.0v now.

I'm just not sure about whether I want this option enabled, or why when disabled, idle voltage skyrockets to 1.33, then when under load back to 1.280.

I also don't like it that I can see the multiplier go from 41-44x under cpu-id under prime95.

I mean what if I'm playing bf3 and c state just decides its time to decrease my multiplier? Is c state doing that?

If it doesn't think there's enough load to keep my multi at 44 under prime95, it won't when I'm gaming.

=/

I also have spread spectrum set to auto right now, if i disable it KABOOM

 

[Soulkeeper]

pstates adjust the clock
cstates deal with the voltages and idle power saving states
ie: speedstep, powernow (collectively pstates+cstates)

your os software reads this stuff from the acpi tables generated by the bios and deals with changing the registers and such, it's a complex dance.
If you have a buggy/incomplete bios, software/os that don't support your cpu then things might not act right

These adjustments happen near instant when working, so I wouldn't worry about them affecting performance.

Enable all the C states

 

[sm625]

CStates shouldnt have anything to do with operational clock speeds. All of them are for sub-idle conditions.

Did you try disabling speedstep?
Is Core Current Limit set to > 150?
Do you have a CPU Core Voltage "Fixed Mode" option?

 

[shwick]

speedstep disabled
change core limie to 300, was 250